One of the checks done by cargo-deny is ensuring all crates have a valid
license. As the rust programs import each other, cargo.toml files
without licenses trigger the check. While I could disable this check
this would be bad practice.
This adds an Apache-2.0 license in the Cargo.toml files.
Some of these files already had a header comment saying it is an Apache
license. As the entire project itself is under an Apache-2.0 license, I
assumed all individual components would also be covered under that
license.
Signed-off-by: Derek Lee <derlee@redhat.com>